Born in the Dou del Bastareny, in the municipality of Gisclareny, not very far away from Bagà, an area of great natural beauty, at an altitude of over one thousand metres. The river suddenly appears in a large rock wall, where it flows out with force, surrounded by trees, boxwood and moss, forming a picture-postcard image. Around it, there are natural spillways such as the Bullidor de Sant Esteve or the Bullidor de la Llet (the Milk Boiler).
The river Bastareny collects water from two valleys and flows into the Llobregat in Guardiola. Although it is not considered an important river, it does have sufficient length to form different and very charming spaces. It is born in the Cadí mountain range; in fact, Bastareny and Cadí Moixeró Natural Park are inseparable. The waters of the mountain range appear and disappear in one of the largest natural areas in Catalonia.